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9.0k Questions 486 Companies08.11.2026
Showing 20 results
Role
Uber logo
Uber
Medium
Data Scientist

Write SQL and Pandas for Uber Trips

Assume 'today' = 2025-09-01. You are given the following schema and small ASCII samples. Tables - riders(rider_id, name, signup_date) - drivers(driver...

Data Manipulation (SQL/Python)
0
0
11 people solved
Oct 13, 2025
Snowflake logo
Snowflake
Medium
Data Scientist

Query seven-day conversion with windows and dedupe

Assume all timestamps are UTC. Treat "today" as 2025-09-01. Define "last 7 days" as the inclusive window [2025-08-26 00:00:00, 2025-09-01 23:59:59]. S...

Data Manipulation (SQL/Python)
2
0
40 people solved
Oct 13, 2025
Snowflake logo
Snowflake
Hard
Data Scientist

Implement DFS with cycle detection and topo order

Implement DFS (recursive and iterative) with topo sort, cycle detection, and timestamps You are given a directed graph G with N nodes labeled 1..N and...

Coding & Algorithms
10
0
84 people solved
Oct 13, 2025
Upstart logo
Upstart
Medium
Data Scientist

Write monthly touches and last-touch SQL

You have two tables tracking marketing touches and downstream conversions. Write SQL to answer the three prompts below. Assume a warehouse like Postgr...

Data Manipulation (SQL/Python)
9
0
68 people solved
Oct 13, 2025
Robinhood logo
Robinhood
Medium
Data Scientist

Write SQL and Python for transaction analytics

You are given user and transaction data. Part A (SQL): Use a join and window functions to answer the prompts below using the following schema and samp...

Data Manipulation (SQL/Python)
10
0
156 people solved
Oct 13, 2025
Meta logo
Meta
Medium
Data Scientist

Define and analyze new-vs-existing activity

Ambiguous product question: Are existing users more active than new users over the last 28 days (ending today = 2025-09-01)? 1) Propose two reasonable...

Data Manipulation (SQL/Python)
3
0
55 people solved
Oct 13, 2025
Tencent logo
Tencent
Medium
Data Scientist

Compute per-player daily cumulative games with windows

Write a SQL query to output, for each player_id and each calendar date present in the data, the cumulative number of games played up to and including ...

Data Manipulation (SQL/Python)
0
0
4 people solved
Oct 13, 2025
Stripe logo
Stripe
Medium
Data Scientist

Design metrics and write SQL for a case

Case: Measure the impact of outreach on subsequent purchases and diagnose anomalies. Define your primary metric and write SQL. Schema and tiny samples...

Data Manipulation (SQL/Python)
0
0
4 people solved
Oct 13, 2025
Upstart logo
Upstart
Medium
Data Scientist

Manipulate data in R with dplyr joins and windows

Using R and dplyr, answer the following using these small tables (dates are ISO strings): transactions(user_id, order_id, order_date, channel, amount)...

Data Manipulation (SQL/Python)
0
0
5 people solved
Oct 13, 2025
Microsoft logo
Microsoft
Medium
Data Scientist

Solve two-pointer, sliding-window, and string tasks

Solve the following three coding tasks: 1) Two-pointer in-place de-duplication: Given a non-decreasing integer array nums and an integer k >= 1, modif...

Coding & Algorithms
6
0
46 people solved
Oct 13, 2025
Capital One logo
Capital One
Medium
Data Scientist

Write SQL to quantify outage revenue loss

A database outage blocked premium membership registrations from 2025-01-01 to 2025-03-31 (inclusive). Members intend to start on intended_start_date, ...

Data Manipulation (SQL/Python)
0
0
6 people solved
Oct 13, 2025
Capital One logo
Capital One
Medium
Data Scientist Locked

Compute profit and break-even for memberships

This question evaluates a candidate's competency in unit economics, algebraic modeling, and sensitivity analysis for loyalty‑program pricing and profi...

Statistics & Math
2
0
47 people solved
Oct 13, 2025
Capital One logo
Capital One
Medium
Data ScientistSenior+

Design a reproducible data pipeline for modeling

You receive raw clickstream events and a user table. Build a reproducible daily pipeline that outputs user-day features for modeling. It must be idemp...

Data Manipulation (SQL/Python)
0
0
5 people solved
Oct 13, 2025
Intuit logo
Intuit
Medium
Data Scientist

Design an idempotent churn ETL pipeline

You must build a daily pipeline that produces month-end churn metrics (logo churn, gross revenue churn, net revenue retention) from streaming subscrip...

Data Manipulation (SQL/Python)
0
0
5 people solved
Oct 13, 2025
Intuit logo
Intuit
Medium
Data Scientist

Compute churn and revenue churn in SQL

You receive monthly end-of-month subscription snapshots and must compute August-2025 churn metrics. Schema and sample data: Table: subscription_monthl...

Data Manipulation (SQL/Python)
0
0
5 people solved
Oct 13, 2025
Uber logo
Uber
Medium
Data Scientist

Compute ETA shift and conversion uplift

Use PostgreSQL (SQL) and brief Python pseudocode. Assume 'today' is 2025-09-01. Schema: - trips(trip_id BIGINT, request_ts TIMESTAMP, city_id INT, rid...

Data Manipulation (SQL/Python)
0
0
6 people solved
Oct 13, 2025
Meta logo
Meta
Medium
Data Scientist Locked

Build a Bayes classifier for reviewer types

This question evaluates Bayesian inference skills, including posterior updating under conditional independence, likelihood modeling for categorical ob...

Machine Learning
2
0
25 people solved
Oct 13, 2025
Capital One logo
Capital One
Medium
Data Scientist

Impute, join, and upsert using SQL and Python

Write both SQL and Python (pandas) to complete the following data-manipulation tasks. Assume today is 2025-09-01 for any time filters. Schema: custome...

Data Manipulation (SQL/Python)
1
0
9 people solved
Oct 13, 2025
Capital One logo
Capital One
Easy
Data Scientist Locked

Find premium share for break-even

This question evaluates a candidate's ability to construct and manipulate a linear financial model and perform break-even analysis using algebra, basi...

Statistics & Math
1
0
35 people solved
Oct 13, 2025
Capital One logo
Capital One
Medium
Data Scientist Locked

Design profitability growth plan

This question evaluates a data scientist's skills in business analytics, experimentation design, and strategic framework development for profitability...

Analytics & Experimentation
3
0
39 people solved
Oct 13, 2025